Forecast the phenotypic ratio for the cross

1.     In rumbunnies spock ears (D) are dominant to earless (d); red eyes (A) are dominant to blue eyes (a); and spinner eyes (E) are dominant nonspinner eyes (e). An individual heterozygous for all three alleles is testcrossed.

a.     Forecast the phenotypic ratio for this cross. (Note: You can do a Punnet square, but it will be a lot easier to use probability.)

b.     Predict the probability that 2 out of 4 progeny from this cross will be earless, with blue spinner eyes.

c.     You perform this cross several more times to determine if these three genes are independently assorting and observe the following results. Answer the following questions:



Observed Number

Spock, red, spinner


Spock, red, nonspinner


Spock, blue, spinner


Spock, blue, nonspinner


Earless, red, spinner


Earless, red, nonspinner


Earless, blue, spinner


Earless, blue, nonspinner


i.     State your null hypothesis.

ii.     Conduct a chi-square analysis to see if your observed data are consistent with your hypothesis.

What are the benefits of genetic engineering

Q1. 1. What are the benefits of genetic engineering versus the potential risks?

2. What are your personal thoughts on genetic engineering? Do you really think genetic engineering provides useful information for the scientific investigation of our natural world or do you think that we must not “mess with Mother Nature”? Describe and support your position.

Q2. Recall Pasteur’s experiment on spontaneous generation. Initially he used sealed and unsealed flasks instead of sealed and swan-necked flasks. Critics claimed that the experiment was inconclusive. Which of the criticisms would be aIDressed by using a swan-necked flask in its place of the unsealed flask?

A decision was made recently to downsize the nursing staff

At a local hospital, a decision was made recently to downsize the nursing staff. The local television station sent a reporter and camera crew to interview the administrator regarding the impact of this action on patient care. After 20 minutes filming the interview, the reporter left. That evening a 15-second segment of the interview was shown, that left an unfavorable impression regarding the impact on quality. The administrator wondered what went wrong. Explain how more control could have been used to send out the message about the downsizing. 

Predict the proportion of gamete types from the testcross

In maize the genes Pl for purple leaves (dominant over green leaves); sm for salmon silk ( recessive for yellow silk) and py for pigmy plant (recessive to normal size) are on chromosome 6 at positions 45, 55 and 65 respectively. Predict the proportion of gamete types from the testcross assuming no interference.

Determine expected frequency of allele and genotype

You are interested in a population of pangolins (scaly anteaters) and find that 49% of the individuals have the homozygous recessive genotype (pp) for a gene of interest. You also find that there are only two phenotypes for this trait, suggesting that the allele “P” is completely dominant over the allele “p.” Given this, determine the following:
The expected frequency of each allele, the expected frequency of each genotype, and the frequency of each phenotype